Stroke is among the top ten causes of death in children. Hemorrhagic stroke represents 50% of strokes and two-thirds of the mortality in childhood. The most common form of hemorrhagic stroke is spontaneous (non-traumatic) intracerebral hemorrhage (ICH). ICH in children has been vastly understudied and potential therapies in adults may not be applicable to children. Before interventional trials and prognostic studies can be undertaken, it is essential to first determine the clinical and pathophysiological factors that affect outcome. In preliminary research by the applicant, odds of death after ICH increased 1.85 times (95% 01:1.07-3.20) per additional 10cc of hemorrhage volume when adjusted for age. ICH locations that were associated poor outcome included the 4th ventricle and the frontotemporal regions. Based on preliminary data, we propose to do the following: Aim 1 is to conduct a prospective longitudinal study of ICH in children to assess time to presentation, etiology, hemorrhage size and other potential predictors of outcome. Hypotheses: 1) Outcome will be worse in children who have larger hemorrhages and in those who have intraventricular hemorrhage, 2) hemorrhage location in patients with poor neurological outcome will be distinct from hemorrhage location in those with good neurological outcome, 3) hemorrhage size and location will be independent predictors of outcome. Therefore, scores for both will be important for creating a formula that predicts outcome. Aim 2 is to determine if measures of intracranial pressure (ICP) and cerebral autoregulation also predict outcome after childhood ICH. A novel indicator of cerebral autoregulation, the cerebral oxygenation index (COx) will be evaluated. COx is measured non-invasively by near infrared spectroscopy (NIRS) and arterial blood pressure. Hypotheses: 1) Children who exhibit failure of cerebral autoregulation as defined as COx >0.3 in the first 24 hours after ICH will have a worse outcome after ICH at 3 and 12 months. The COx may provide a non-invasive measure of cerebral autoregulation that could be used for patient management. Public Health Relevance: This study will provide a better understanding of the factors that predict neurological outcome after childhood ICH, an important cause of mortality and life-long disability in children, and will lay a foundation for future advances in patient care including treatment trials. [unreadable]